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Shedding New Light on Forensic TimelinesThe development of novel, nondestructive technologies for rapid analysis of evidence discovered at crime scenes is pertinent to our criminal justice system to solve the millions of violent crimes that occur each year. Without a witness, establishing the precise timeline of a crime is difficult. Therefore, technologies based on sensitive, nondestructive techniques are needed to evaluate evidence and create such a timeline. We propose the use of Raman spectroscopy to analyze the age of bloodstains for potential use as a forensics tool. Previous studies have revealed Raman spectroscopy is sensitive to changes in blood analyte concentration and different oxidative states of hemoglobin. Raman spectroscopy could allow for rapid comparison of spectra from blood stains of unknown age to spectra of known age with high temporal accuracy. Though further investigation into other substrates and biochemical components should be performed, our study reveals Raman spectroscopy has the potential to accurately and nondestructively determine the age of a bloodstain for use in criminal investigations.
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ICP-MS Speciation Analysis: Three Roles of SeleniumThe element selenium plays three distinct roles in biological processes, functioning in turn as a toxicant, a chemopreventive agent, and a heavy metal antagonist. This article discusses current research associated with each role, and how ICP-MS can be employed to better understand and utilize selenium's properties.
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Grating Corrected Laser Stabilization: A Case Study in Pharmaceutical Raw Material IdentificationThe authors present a novel technique for obtaining very high stability and reproducibility of a Raman spectrum, using grating corrected laser stabilization. An externally stabilized laser with a grating spectrometer provides exceptional quantum efficiency in the entire dynamic range. These components then are used to build a library of pharmaceutical raw materials and tested on samples of unknown material.
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Correlative Raman Imaging: Geoscience Applications (Sept 2023)See how Raman microscopy in combination with SEM, AFM, topographic imaging, and other methods can characterize properties of geoscience samples.
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A New Approach to Simultaneous Raman and IR Spectral SearchesA new system for multitechnique spectral searching is described that utilizes analysis of several hit lists resulting from spectral similarity searches performed simultaneously in reference databases for multiple complementary analytical techniques. This paper demonstrates the benefits of this multitechnique approach using the complementary techniques of IR and Raman spectroscopy.
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Test of an In Vivo Method to Detect Chloroplast Division in Crop Plants, Part III: Statistical Proofs of Observation and General Utility of the Method (PDF)This article is the third installment in a series about a novel spectrofluorometric method that allow for in vivo observation of the division of chlorplast populations in leaves of Arabidopsis thalania.
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LC–MS Characterization of Mesquite Flour ConstituentsGiven the wide range in polarity of the components of mesquite flour, it is advantageous to study the health benefits of this flour using methods that combine the complementary approaches of reversed-phase and aqueous normal phase LC.
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Are You Ready for the Latest Data Integrity Guidance? Part 2: Computerized Systems, Outsourcing, Quality, and Regulatory OversightWe continue our explanation of the new PIC/S data guidance.
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A New Approach to Simultaneous Raman and IR Spectral SearchesA new system for multitechnique spectral searching is described that utilizes analysis of several hit lists resulting from spectral similarity searches performed simultaneously in reference databases for multiple complementary analytical techniques. This paper demonstrates the benefits of this multitechnique approach using the complementary techniques of IR and Raman spectroscopy.
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Using High-Resolution LC–MS to Analyze Complex SampleThe authors discuss the use of high-resolution LC-MS to analyze complex samples in regulated environments such as food and animal-feed analysis.
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Molecular Spectroscopy Workbench: A Comparison between Validating Laboratory and Process Near-Infrared Spectrophotometers (PDF)The author describes applying validation principles originally designed for lab instruments to process instruments.
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High performance Mass Spectroscopy Begins with High-Performance SeparationsThis article discusses the role of recent LC developments in th quest for greater sensitivity, more complete sample characterization, and greater productivity.
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A New Tool for Mass Analysis of Unknown Molecules: High-Resolution Multistep Tandem MS with Wide Dynamic Range Quantitative AnalysisMass spectrometers are effective for identifying and quantifying unknown molecules, such as disease-related proteins and small molecules in pharmaceutical research and medical diagnosis. In addition, mass spectrometry (MS) can be particularly powerful when analyzing molecules with complex structures, such as posttranslationally modified proteins. Among various MS approaches, high-resolution multistep tandem MS (MS-MS) is an emerging methodology for accurate identification of complex molecules. In this article, we describe a new approach for mass analysis with enhanced quantitative capability combined with high-resolution multistep MS-MS, where the dynamic range of quantitation covers four orders of magnitude.
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Efficient Raman Lasing in Tapered Silicon WaveguidesThe authors review the operating principles of a silicon Raman laser and show that by introducing a longitudinal variation of the waveguide width in the cavity, the lasing efficiency can be increased significantly.
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A Comprehensive Study of WSe2 Crystals Using Correlated Raman, Photoluminescence (PL), Second Harmonic Generation (SHG), and Atomic Force Microscopy (AFM) ImagingUsing confocal Raman imaging and other advanced measurement techniques, we study the localized strain characteristics of tungsten diselenide (WSe2), an important nanomaterial used for optoelectronic device applications.
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New Sample Fractionation Strategies for Proteomic Analyses by LC–MSMass spectrometry has long been a preferred tool for protein identification and biomarker discovery, but preparation of biological samples remains a challenge. Hindrances include the wide range of protein concentrations, sample complexity, and loss or alteration of important proteins due to sample handling. This article describes recent developments in sample fractionation technologies that are overcoming these challenges in interesting ways and are enabling in-depth proteomic studies that were not possible in the past.
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Bottled Water: Popular, But Is It Safe?Bottled water has become increasingly popular over the past several years for convenience and safety. In some areas where publicly supplied tap water is contaminated or contains bacteria, this assumption is valid. However, in areas with clean tap water, the presence of bottled water can be controversial because it might be less clean than the local tap. This article discusses the analysis of inorganic contaminants in bottled water, including regulated contaminants and bromate. Detection limit considerations and speed of analysis also are discussed.
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Increasing the Enhancement of SERS with Dielectric Microsphere ResonatorsSurface-enhanced Raman spectroscopy (SERS) is a widely studied technique capable of adding single-molecule detection capability to the rich information provided by Raman spectroscopy. in this aricle, the authors show an additional system gain of more than two orders of magnitude to SERS by using a dielectric microsphere resonator to capture and excite the target system.
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Measurement of Metabolic Stability Using SIM and Identification of Metabolites by Data-Dependent full-Scan MS-MS and CNL ScanningIn this article, the role of a triple-quadrupole mass spectrometer in performing in vitro studies of compound metabolic stability and identification of Phase I and II metabolites is demonstrated.
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Using FT-MS to Detect Indoor Chemical ContaminationA transportable miniature Fourier-transform ion cyclotron resonance mass spectrometer is used to identify chemical species and remove isobaric interferences in gas analysis. Experimental results use real time direct analysis without the need for additional separation.
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Measurement of Metabolic Stability Using SIM and Identification of Metabolites by Data-Dependent full-Scan MS-MS and CNL ScanningIn this article, the role of a triple-quadrupole mass spectrometer in performing in vitro studies of compound metabolic stability and identification of Phase I and II metabolites is demonstrated.
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An Expanding Role: The Use of Ultrahigh Performance LC–TOF-MS, GC–TOF-MS, Accurate Mass, and Isotope Modeling for Screening Complex MixturesUltrahigh performance liquid chromatography (LC)–time-of-flight mass spectrometry –(TOF-MS) and gas chromatography (GC)–TOF-MS are powerful approaches for screening target compounds and identifying or characterizing nontarget compounds in complex mixtures. The combination of accurate mass data and newly developed software enables truly generic screening methods with TOF-MS, and the confident detection, identification, and confirmation of small molecules in a range of application areas.
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A New Approach to Simultaneous Raman and IR Spectral SearchesA new system for multitechnique spectral searching is described that utilizes analysis of several hit lists resulting from spectral similarity searches performed simultaneously in reference databases for multiple complementary analytical techniques. This paper demonstrates the benefits of this multitechnique approach using the complementary techniques of IR and Raman spectroscopy.
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IMS for Cleaning Verification (PDF)The need to verify cleaning between manufacturing runs presents a special challenge to the analytical chemist. In this article, the principles of ion mobility spectrometry are described, its performance is compared to HPLC for the analysis of cleaning validation samples, and findings are presented from a study to establish the feasibility of using IMS in validating a cleaning verification method.
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Measurement of Metabolic Stability Using SIM and Identification of Metabolites by Data-Dependent full-Scan MS-MS and CNL ScanningIn this article, the role of a triple-quadrupole mass spectrometer in performing in vitro studies of compound metabolic stability and identification of Phase I and II metabolites is demonstrated.
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FAIMS Removes Chemical Background and Interference from the Analysis of Linoleic Acid in Cancer Cell ExtractsAssay sensitivity is the lowest concentration at which a targeted analyte can be measured and is often limited by chemical background or co-eluting interferences. FAIMS in combination with liquid chromatography (LC) and zero neutral loss tandem MS was used to remove chemical background and co-eluting interferences from the analysis of linoleic acid in cancer cell extracts. Concentration of endogenous linoleic acid was determined from back-calculation of standard calibration samples fortified with deuterium-labeled linoleic acid. No internal standard was used. LC–MS-MS analysis of the cancer cell extracts resulted in an increase in signal-to-noise ratio of 10-fold. The assay sensitivity was increased 10 times over the traditional LC–MS-MS experiment exclusively due to the new FAIMS technology.
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Reliable Substrate Technology for Surface-Enhanced Raman SpectroscopyThe acquisition of Raman spectra can be eased greatly through the use of surface-enhanced Raman spectroscopy (SERS). In this article, the authors discuss a new substrate technology that delivers reliable and consistent surface enhancement.
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New Sample Fractionation Strategies for Proteomic Analyses by LC–MSMass spectrometry has long been a preferred tool for protein identification and biomarker discovery, but preparation of biological samples remains a challenge. Hindrances include the wide range of protein concentrations, sample complexity, and loss or alteration of important proteins due to sample handling. This article describes recent developments in sample fractionation technologies that are overcoming these challenges in interesting ways and are enabling in-depth proteomic studies that were not possible in the past.
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Qualitative and Quantitative Metabolite Identification for Verapamil in Rat Plasma by Sub-2-μm LC Coupled with Quadrupole TOF-MSAn effective metabolite identification study should ideally include both qualitative and quantitative information that for both identifying metabolites, and determining the rate of clearance and the metabolic routes of the parent drug. Liquid chromatography–mass spectrometry (LC–MS) is considered the standard analytical technique for metabolite identification studies. To date, however, qualitative and quantitative information has always been obtained from two separation platforms: quadrupole time-of-flight (QTof) MS for the exact mass full-scan qualitative study, and tandem quadrupole MS for the multiple reaction monitoring (MRM) quantitative study. With advancements to QTof instrumentation, specifically, recent improvements in sensitivity and dynamic range, it is now possible to perform both qualitative and quantitative experiments on a single QTof mass spectrometer. This article describes a workflow that allows simultaneous qualitative and quantitative metabolite identification studies to be..
